The Cypriot ex-wife of an Egyptian man who authorities say admitted hijacked a domestic EgyptAir flight has said he is an "extremely dangerous man" who used drugs and beat her and their children.

Marina Paraschou strongly rejected media reports suggesting that 59-year-old Seif Eddin Mustafa hijacked the Airbus A320 with 72 passengers and crew on board and threatened to blow it up with a fake suicide belt out of love for her.

In an interview published on Thursday in leading Cypriot daily Phileleftheros, Ms Paraschou said it is a "lie" that Mustafa asked to speak to her, and that police who brought her to Cyprus' main Larnaca airport where the plane was diverted only asked her to identify his voice.

Cypriot officials, who described Mustafa as "psychologically unstable", said he had asked police negotiators during Tuesday's hijacking to deliver a letter to Ms Paraschou in which he demanded the release of 63 dissident women imprisoned in Egypt.

The six-hour ordeal ended peacefully when police arrested Mustafa after all passengers and crew were released.

During a court hearing on Wednesday, a police prosecutor said Mustafa told authorities after his arrest: "What's someone supposed to do when he hasn't seen his wife and children in 24 years and the Egyptian government won't let him?"

But Ms Paraschou suggested in the interview that it was all a ruse.

She said: "This man never cared for his children for one minute, either when he lived here or when he went away.

"He only offered pain, misery and terror. And even now when he's in police custody, my children and I are afraid."

In a separate interview with daily Politis also published on Thursday, Ms Paraschou said Mustafa used her as an "excuse" to seek asylum in Cyprus.

Ms Paraschou told Phileleftheros she married Mustafa in 1985 when she was 20.

The couple divorced five years later and since then had only once made contact when she called him several years later to say that their teenage daughter - one of four children the couple had together - had been killed in a car accident.

"What do I care? It doesn't matter she was killed," Ms Paraschou said Mustafa had told her.

She said while married, the couple lived in her parents' home and that Mustafa never held down a job, beating his children when he could not support his drug habit.

Ms Paraschou said Mustafa was a "fanatical" Palestine Liberation Organisation supporter who bragged about participating in the killing of three Israeli soldiers and was jailed for four years in Syria.

She said Mustafa's tattoos and some "items" she did not identify betrayed Mustafa's "connections with dark things".

Egypt's interior ministry said Mustafa had a long criminal record but had finished serving a one-year prison term in March 2015.

Cyprus police said that Mustafa's criminal record on the island stretched back to 1988, when he was convicted on six counts of forging passports and handed a suspended sentence.

He was later deported to Egypt following domestic violence charges by Ms Paraschou.

He re-entered Cyprus on an assumed Qatari identity, but was tracked down and again deported to Egypt in 1990.

Meanwhile, in Egypt, Mustafa's 57-year old sister gave a different account, saying his brother's life was focused on how to get to see his children and that his only offences were related to forging documents so he could travel to see them.

"For 24 years, my brother wasted his life in prison and attempts to travel and see his children," Fekriya Mustafa said.

She said he phoned her from the plane twice and told her that he had hijacked the aircraft - but she believed he was joking until she saw his picture on TV news.

She added that she last saw him a week ago but had no clue what he would do.

"I had no idea this will happen," she said. "He was depressed because of the children. He has no work, no life, nothing."

The sister said he had no violent past but that he had beaten his children to "discipline them". She made no mention of him beating up his ex-wife.